diff --git a/include/spdlog/sinks/wincolor_sink.h b/include/spdlog/sinks/wincolor_sink.h
index e73a1ae3..5555d801 100644
--- a/include/spdlog/sinks/wincolor_sink.h
+++ b/include/spdlog/sinks/wincolor_sink.h
@@ -54,7 +54,7 @@ public:
     {
         auto color = colors_[msg.level];
         auto orig_attribs = set_console_attribs(color);
-        WriteConsoleA(out_handle_, msg.formatted.data(), msg.formatted.size(), nullptr, nullptr);
+        WriteConsoleA(out_handle_, msg.formatted.data(), static_cast<DWORD>(msg.formatted.size()), nullptr, nullptr);
         SetConsoleTextAttribute(out_handle_, orig_attribs); //reset to orig colors
     }
 
@@ -113,4 +113,4 @@ typedef wincolor_stderr_sink<std::mutex> wincolor_stderr_sink_mt;
 typedef wincolor_stderr_sink<details::null_mutex> wincolor_stderr_sink_st;
 
 }
-}
\ No newline at end of file
+}